Promoters

Abstract

A promoter is a segment of a gene of about 100–400 base pairs that comprises the transcription initiation site and a collection
of short deoxyribonucleic acid (DNA) sequences that bind proteins involved in regulating transcription. The proteins that
bind to the promoter mediate the recruitment of a ribonucleic acid (RNA) polymerase to the initiation site and play a major
role in dictating when, and in which cells, the gene is expressed.

Core promoter elements. Three DNA elements that are commonly found in core promoters for mammalian genes are shown, along
with the consensus sequence for each element. Inr: initiator element; DPE: downstream promoter element; Py: C or T; N: any nucleotide.